Network system, communication method for use in network system and host device

Abstract

A host device connected to a network includes a storage unit configured to store first identification information dynamically assigned to a device connected to the network and second identification information unique to the device, and an updating unit acquiring the first identification information and the second identification information from the device and updating the first identification information stored in the storage unit with the acquired first identification information based on the acquired second identification information.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to an art for communication in an environment where identification information dynamically changes in a network, and more particularly, to an art for enabling communication by following a change in identification information even when no name server is available.[0002]In a network system using a TCP / IP, an IP address is dynamically assigned to a device which is connected to a network by utilization of the art of DHCP (Dynamic Host device Configuration Protocol). In relation to the DHCP, a DHCP server assigns IP addresses to devices which have been connected to the network, in the sequence in which the devices have been connected to the network. When the device assigned a particular IP address leaves the network, the DHCP server recovers the IP address assigned to the device and possibly re-uses the IP address by assigning the IP address to another device.[0003]Consequently, when a device having once been assigned an IP a...

AI Technical Summary

Benefits of technology

The present invention provides a method for enabling continuous communication without the need for a name server in a network where devices are dynamically assigned different identification information. This is achieved by storing first identification information and second identification information in a host device and an updating unit, which can acquire the first identification information and the second identification information from the device and update the first identification information based on the second identification information. The method can also include transmitting inquiry information to the device for confirming the exist of a communicable device with the host device and receiving response information from the device. The technical effect of this invention is to enable seamless communication without the need for a name server in a network where devices are dynamically assigned different identification information.

Problems solved by technology

Consequently, when a device having once been assigned an IP address upon connection with the network and having left the network is again connected to the network, the device is not guaranteed to be assigned the same IP address as that assigned previously.

Hence, if the IP address is changed, communication cannot be continued unless a newly-assigned IP address is acquired.

For instance, in a situation where a host device and a printer are connected to a network, when the IP address of the printer is changed as a result of the power of the printer being turned off and again turned on, the host device cannot perform printing by use of the printer in subsequent operations, unless the host device acquires a new IP address of the printer

However, in a LAN environment of extremely small scale, such as that found in an ordinary home, introduction of a name server such as a DNS is not realistic for various reasons, such as introduction costs or a deficiency in network management skills.

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